7 research outputs found

    A search for rare BDμ+μB \to D \mu^+\mu^- decays

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    A search for rare BDμ+μB \rightarrow D \mu^+ \mu^- decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1^{-1}. No significant signals are observed in the non-resonant μ+μ\mu^+\mu^- modes, and upper limits of B(B0D0μ+μ)<5.1×108\mathcal{B}(B^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 5.1 \times 10^{-8}, B(B+Ds+μ+μ)<3.2×108\mathcal{B}(B^+ \rightarrow D_s^+ \mu^+ \mu^-) < 3.2 \times 10^{-8}, B(Bs0D0μ+μ)<1.6×107\mathcal{B}(B_s^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 1.6 \times 10^{-7} and fc/fuB(Bc+Ds+μ+μ)<9.6×108f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ \mu^+ \mu^-) < 9.6 \times 10^{-8} are set at the 95 % confidence level, where fcf_c and fuf_u are the fragmentation fractions of a BB meson with a cc and uu quark respectively in proton-proton collisions. Each result is either the first such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a J/ψμ+μJ/\psi \rightarrow \mu^+ \mu^- decay. The branching fraction of Bc+Ds+J/ψB_c^+ \rightarrow D_s^+ J/\psi multiplied by the fragmentation-fraction ratio is measured to be fc/fuB(Bc+Ds+J/ψ)=(1.63±0.15±0.13)×105f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ J/\psi ) = (1.63 \pm 0.15 \pm 0.13) \times 10^{-5}, where the first uncertainty is statistical and the second systematic.A search for rare BDμ+μB \rightarrow D \mu^+ \mu^- decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb1^{-1}. No significant signals are observed in the non-resonant μ+μ\mu^+\mu^- modes, and upper limits of B(B0D0μ+μ)<5.1×108\mathcal{B}(B^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 5.1 \times 10^{-8}, B(B+Ds+μ+μ)<3.2×108\mathcal{B}(B^+ \rightarrow D_s^+ \mu^+ \mu^-) < 3.2 \times 10^{-8}, B(Bs0D0μ+μ)<1.6×107\mathcal{B}(B_s^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 1.6 \times 10^{-7} and fc/fuB(Bc+Ds+μ+μ)<9.6×108f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ \mu^+ \mu^-) < 9.6 \times 10^{-8} are set at the 95% confidence level, where fcf_c and fuf_u are the fragmentation fractions of a BB meson with a cc and uu quark respectively in proton-proton collisions. Each result is either the first such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a J/ψμ+μJ/\psi \rightarrow \mu^+ \mu^- decay. The branching fraction of Bc+Ds+J/ψB_c^+ \rightarrow D_s^+ J/\psi multiplied by the fragmentation-fraction ratio is measured to be fc/fuB(Bc+Ds+J/ψ)=(1.63±0.15±0.13)×105f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ J/\psi ) = (1.63 \pm 0.15 \pm 0.13) \times 10^{-5}, where the first uncertainty is statistical and the second systematic

    Measurement of the CKM angle γ in the B0→DK *0 channel using self-conjugate D→ KS0h+ h- decays

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    A model-independent study of CP violation in B-0 -&gt; DK (*0) decays is presented using data corresponding to an integrated luminosity of 9 fb(-1) collected by the LHCb experiment at centre-of-mass energies of v s = 7, 8 and 13TeV. The CKM angle. is determined by examining the distributions of signal decays in phase-space bins of the self-conjugate D. K(S)(0)h(+) h(-) decays, where h = p, K. Observables related to CP violation are measured and the angle. is determined to be. = (49+22 -19).. Measurements of the amplitude ratio and strong-phase difference between the favoured and suppressed B-0 decays are also presented

    A search for rare B → Dμ+μ- decays

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    A search for rare B. D mu+ mu- decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1. No significant signals are observed in the non-resonant mu+ mu- modes, and upper limits of B -&gt; B0. D0 mu+ mu- &lt; 5.1 x 10-8, B B+. D+ s mu+ mu- -&gt; &lt; 3.2 x 10-8, B -&gt; B0 s. D0 mu+ mu--&gt; &lt; 1.6 x 10-7 and fc/fu center dot B B+ c. D+ s mu+ mu--&gt; &lt; 9.6 x 10-8 are set at the 95% confidence level, where fc and fu are the fragmentation fractions of a B meson with a c and u quark respectively in proton-proton collisions. Each result is either the first such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a J/.. mu+ mu- decay. The branching fraction of B+ c. D+ s J/. multiplied by the fragmentation-fraction ratio is measured to be fc fu center dot B -&gt; B+ c. D+ s J/.-&gt; = (1.63 +/- 0.15 +/- 0.13) x 10-5, where the first uncertainty is statistical and the second systematic

    Evidence for the decays B0 → (D)over-bar(*)0φ and updated measurements of the branching fractions of the Bs0 → (D)over-bar(*)0φ decays

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    Evidence for the decays B-0 -&gt; (D) over bar (0)phi and B-0 -&gt; (D) over bar (*0) phi is reported with a significance of 3.6 sigma and 4.3 sigma, respectively. The analysis employs pp collision data at centre-of-mass energies root s = 7, 8 and 13TeV collected by the LHCb detector and corresponding to an integrated luminosity of 9 fb(-1). The branching fractions are measured to beB(B-0 -&gt; (D) over bar (0)phi) = (7.7 +/- 2.1 +/- 0.7 +/- 0.7) x 10(-7),B(B-0 -&gt; (D) over bar (*0)phi) = (2.2 +/- 05 +/- 0.2 +/- 0.2) x 10(-6).In these results, the first uncertainty is statistical, the second systematic, and the third is related to the branching fraction of the B-0 -&gt; (D) over bar K-0(+) K- decay, used for normalisation. By combining the branching fractions of the decays B-0 -&gt; (D) over bar ((*)0)phi and B-0 -&gt; (D) over bar ((*)0)omega, the omega-phi mixing angle delta is constrained to be tan(2)delta = (3.6 +/- 0.7 +/- 0.4) x 10(-3), where the first uncertainty is statistical and the second systematic. An updated measurement of the branching fractions of the B-s(0) -&gt; (D) over bar ((*)0).phi decays, which can be used to determine the CKM angle gamma, leads toB(B-s(0) -&gt; (D) over bar (0)phi) = (2.30 +/- 0.10 +/- 0.11 +/- 0.20) x 10(-5),B(B-s(0) -&gt; (D) over bar (*0)phi) = (3.17 +/- 0.16 +/- 0.17 +/- 0.27) x 10(-5)
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